The following meanings for the abbreviations used in this specification apply:    3GPP 3rd generation partnership project    BW Bandwidth    CC Component carrier    CQI Channel quality indicator    DL Downlink    eNode-B LTE base station (also referred to as eNB)    LTE Long term evolution    LTE-A LTE-Advanced    MCS Modulation and coding scheme    PRB Physical resource block    RRC Radio resource control    RSRQ Reference signal received quality    SNIR Signal to Noise and Interference Ratio    TS Technical specification    UE User equipment    UL Uplink
Embodiments of the present invention relate to systems with component carrier aggregation (or channel bonding), where the total system bandwidth consists of set of component carriers as illustrated in FIG. 3.
The term “component carrier” (CC) is defined for LTE-Advanced (e.g., 3GPP TR 36.814 V.1.0.0). One CC basically corresponds to one carrier, where similar channels as for LTE Rel'8 are defined. The numerology for one CC follows that of Rel'8. Simultaneous transmission on multiple CCs is possible via so-called carrier aggregation, as described in the following.
The component carriers can be next to each other (i.e. forming one contiguous system bandwidth), or they can be arranged to have a carrier frequency spacing much larger than their individual bandwidths. FIG. 3 shows an example of carrier aggregation with non-contiguous bands, in which the total system bandwidth contains a set of component carriers BW1, BW2, . . . , BWN, having carrier frequencies f1, f2, . . . , fN.
The ongoing standardization of LTE-Advanced in 3GPP (currently in the study item phase) assumes carrier aggregation to form bandwidths of up to 100 MHz by having aggregation of up to 5 component carriers of 20 MHz each. Different transport blocks with different modulation and coding schemes (MCS) can be transmitted on the different component carriers, although transmitted to the same user. In order to facilitate such schemes with efficient frequency domain link adaptation scheduling, the UEs must provide frequency selective channel quality indicator (CQI) feedback. However, in order have a reasonable uplink (UL) CQI overhead, new CQI reporting schemes are likely to be required when extending the system bandwidth from 20 MHz (max bandwidth for LTE Rel'8) to 100 MHz.
Hence, new CQI reporting schemes for LTE-Advanced with multiple component carriers should be provided.